New York, Dec 23 (IANS): Just 20 minutes of weight training can reduce abdominal fat that a lot of men tend to gain as they age, research has suggested.

Combining weight training and aerobic activity leads to even better results in terms of maintaining a healthy weight and waistline, the findings showed.

"This study underscores the importance of weight training in reducing abdominal obesity, especially among the elderly," said senior author of the study Frank Hu, a professor of nutrition and epidemiology at Harvard School of Public Health (HSPH).

The researchers studied the physical activity, waist circumference, and body weight of 10,500 healthy US men aged 40 between 1996 and 2008.

Their analysis included a comparison of changes in participants' activity levels over the 12-year period to see which activities had the most effect on the men's waistlines.

Those, who increased the amount of time spent in weight training by 20 minutes a day, had less gain in their waistline (-0.67 cm) compared with men who similarly increased the amount of time they spent on moderate-to-vigorous aerobic exercise (-0.33 cm), and yard work or stair climbing (-0.16 cm).

Those who increased their sedentary behaviours, such as TV watching, had a larger gain in their waistline.

"Engaging in resistance training or, ideally, combining it with aerobic exercise could help older adults lessen abdominal fat while increasing or preserving muscle mass," said lead author Rania Mekary, researcher at HSPH.

The study appeared online in the journal Obesity.